What are the most common scientific myths

Faith and Truth in Science: Science myths are persistent

Interest in this topic is slowly increasing, and projects such as the Human Connectome Project of the US National Institutes of Health and the Blue Brain Project of the École polytechnique fédérale de Lausanne are now looking more closely at how the connections in the brain influence its functions.

Fourth legend: everyone learns best in their own way

The size of our brain is also associated with other properties. For example, there is a common myth that each of us would learn best in our own preferred way. A so-called "verbal type" should learn best through verbal instructions and a "visual" person should learn most effectively using graphics and diagrams.

In essence, this harbors two truths: Many people prefer a certain way of conveying information, and the best learning success can be achieved when learning content is presented in several ways. If you bring people's preference together with their will to learn and see them as individually different, the myth has already been created.

"There is a real core, a little wishful thinking and an emotional bias in favor of the 'learning style' idea," says Howard-Jones. But as with sweets, pornography and television, the following also applies here: "Not everything we want is also good or right for us," explains the learning psychologist Paul Kirschner from the Open University of the Netherlands.

As early as 2008, four researchers in cognitive neuroscience compared the pros and cons of different learning styles. Only a few studies had so far seriously questioned the ideas - where they did it, it was found that a type of presentation preferred by the test subjects did not affect the learning success at all. The authors point to a "worrying disparity" between the tremendous popularity of the idea of ​​an individual learning style and the lack of credible evidence to support it.

However, that hasn't stopped a very lucrative industry from putting books and tests on the market for around 71 different learning methods. The scientists themselves upheld the legend for a long time by quoting the different learning styles in more than 360 publications over the past five years. "Especially in the development of questionnaires and surveys in the population, the ideas are still present, not least because of the great self-interest in them," says Richard Mayer, who researches as a learning psychologist at the University of California in Santa Barbara.

As research into learning techniques over the past decades has shown, there are of course methods to improve learning success, such as summarizing or explaining what has been learned by the student. Except for people with learning difficulties, almost all people learn best from a mixture of words and graphics rather than just one type of representation.

But the myth of individual learning styles makes it difficult for new, proven concepts to penetrate the classroom at all. When Howard-Jones tried it, many teachers didn't even listen to him. "It rather disaffected them because they had already invested so much hope, time and effort," he says. "They no longer believe that science can support learning and teaching methods at all."

Fifth Legend: The world population is growing exponentially and that will mean our end

When Reverend Thomas Malthus prophesied in 1798 that uncontrolled, exponential growth would lead to hunger and poverty, he fueled the first fears of overpopulation on earth.

However, the world population has never grown and is not growing exponentially today. And it probably never will, says Joel Cohen, a population researcher at Rockefeller University in New York City. The number of people on the globe is currently only growing half as fast as it was before 1965. According to current estimates, 7.3 billion people are currently living and by 2050 the figure is set to reach 9.7 billion. Nevertheless, horror scenarios are constantly strengthened: For example, the famous physicist Albert Bartlett has given more than 1742 lectures on exponential population growth and the dire consequences since 1969.

In addition, the world's population has enough to eat. According to calculations by the World Food Organization (FAO), increasing global food production is even outstripping population growth. In the form of grain alone, we produce so many calories that between ten and twelve billion people could feed on them. Hunger and malnutrition can still be found worldwide because more than 55 percent of the food produced ends up in cattle feed, fuels and other materials or even in the garbage, says Cohen. What's left is also unevenly distributed because the rich get a lot of it and the poor get little. Even water is not really scarce on our globe, but 1.2 billion people still live in areas with water scarcity.

"The so-called overpopulation is not - the crux of the matter is more poverty," explains demographer Nicholas Eberstadt of the American Enterprise Institute, a conservative think tank in Washington DC. Instead of examining why poverty exists in the first place and how we could sustainably support a growing population, in his opinion scientists and biologists talk past each other and only discuss definitions and reasons for overpopulation.

Regarding an economic system that only benefits the rich, Cohen adds: "Even those who know all the facts use the existing system as an excuse not to have to deal with the current problems".

The most persistent legends

"Nature" asked doctors and scientists what they thought were the most frustrating medical myths. This came out:

Vaccines cause autism
Even if vaccines involve risks, a link to neurological disorders has been refuted in many studies.

The mechanism of action of paracetamol is well known
Despite various studies, there are only indications of the mode of action of this and other common drugs.

The brain is isolated from the immune system
The brain has its own immune cells; only recently was a lymphatic system discovered, which connects the brain to the immune system of the rest of the body.

Homeopathy works
Does not she.

Cohen and many other researchers interviewed in the run-up to this article see little chance of shattering common myths such as overpopulation, but he affirms that it is imperative that we prevent further myths. Many of these myths could develop because the narrow conclusions of a particular work were extrapolated by other researchers, as happened, for example, with the free radicals. This "infiltration of the original interpretation", as Spitzer roughly calls the phenomenon, can lead to misinterpretations that are difficult to eradicate again. Something like this could be prevented by "always ensuring that an extrapolation is also justified and that we do not go too far beyond the known data," suggests Spitzer. Besides, we just have to talk to each other, says Howard-Jones. Scientists need to communicate and explain their ideas well, not simply spreading catchy messages.

Once a myth is born, it often persists. As studies in psychology show, trying to destroy a myth tends to reinforce it. In a study in the USA, parents were confronted with statements that speak for a vaccination - their willingness to have their children vaccinated was rather reduced as a result. In another study, misleading claims by politicians tended to reinforce false assumptions. "Myths can hardly be eradicated," says Kirschner. "The more you prove otherwise, the more people believe in it."

The article originally appeared in "The science myths that will not die" in "Nature".